Calcium is the “most abundant metallic element in the human body, 99 percent of which can be found in our bones and teeth (about 2 lbs. of it!).”  The remaining 1 percent of calcium can be found in the blood and other tissues.”  Calcium is a mineral found in our body most often known for keeping our bones strong. More specifically, calcium is known to: 
Help blood vessels and muscles work properly.
Help release hormones and enzymes that keep your body working properly.
Help your nerves carry messages throughout your body.
Help control important nutrients, such as magnesium, phosphorus, and potassium.
Calcium is crucial in maintaining a homeostatic level of health; this mineral has also been researched in relation to cancer, specifically breast cancer.
Calcium and Breast Cancer
Some scientific studies have discovered a link between calcium and vitamin D levels and their relationship with breast cancer. For example, a 2009 study found that:
“a low vitamin D status and inadequate calcium intake are important risk factors for various types of cancer. Ecological studies using solar UV-B exposure as an index of vitamin D3 photoproduction in the skin found a highly significant inverse association between UV-B and mortality in fifteen types of cancer. Of these, colon, rectal, breast, gastric, endometrial, renal and ovarian cancer exhibit a significant inverse relationship between incidence and oral intake of calcium.”
What this means is that the lack of sufficient amounts of calcium and vitamin D were revealed to have increased the risk for certain cancers, including breast cancer. One conclusion drawn from this study is that supplementation (which ensures a person receives adequate amounts of each) of calcium and vitamin D “is required for optimal chemo-prevention of cancer.”
A second, independent study conducted took place in the form of a randomized trial found:
“that included nearly 1,200 healthy, postmenopausal Nebraska women, individuals were randomly assigned to receive daily calcium supplementation alone (300–600 mg elemental calcium), calcium supplementation (300–600 mg elemental calcium) combined with vitamin D supplementation (1000 IU), or a placebo for 4 years. The incidence of all cancers combined was approximately 60 percent lower for women who took the calcium plus vitamin D supplements compared with women who took the placebo. A lower risk of all cancers combined was also observed for women who took calcium supplements alone, but this finding was not statistically significant.” 
This study, although unrelated to the first mentioned, further supports that adequate amounts of calcium, whether absorbed naturally through a rich diet or supplements, helps to reduce the risk of cancer, specifically breast cancer. Therefore, it is important that you receive calcium daily and on a regular basis; this is most commonly done through a balanced diet, although supplements are also readily available.
Integrating Calcium in Your Diet
Calcium is most frequently absorbed into the body through the foods we eat, including dairy products. It is important to eat calcium-rich food on a regular basis because “each day, we lose calcium through our skin, nails, hair, sweat, urine, and feces, but our bodies cannot produce new calcium.” Our body usually restores its calcium levels naturally, through our diet. Calcium is found in a variety of food sources, some of which include: 
Plain or fruit yogurt
Milk (whole, non-fat, reduced-fat, buttermilk, or soy)
It is important to note that “Vitamin D is key to absorbing and using calcium;” therefore it is crucial that you are also receiving adequate amounts of Vitamin D.  To learn more about Vitamin D, click here.
Most people receive enough calcium through a balanced diet that includes dairy and greens, especially if their Vitamin D levels are optimal. However, some people integrate supplements into their diets as well because “if your body doesn’t get enough calcium and vitamin D to support important functions, it takes calcium from your bones. This is called losing bone mass. Losing bone mass makes the inside of your bones become weak and porous,” increasing the risk of developing osteoporosis.6This is more common among postmenopausal women, those that are lactose intolerant or avoid dairy products, and vegans (who avoid all animal products and byproducts). Should you want to learn more about integrating calcium-rich foods or calcium supplements into your diet, consult your doctor or physician.
For More Information
Calcium is a crucial component of our overall health; it strengthens our bones and helps our body absorb other key nutrients such as magnesium. Most balanced diets contain adequate levels of calcium, especially if you are receiving proper amounts of Vitamin D. To inquire about integrating calcium into your diet, consult your physician. You can also contact our medical team here; we are happy to assist you.
Pedersen, Traci. “Facts About Calcium.” LiveScience.2016.
“Calcium: What’s Best for Your Bones and Health” Harvard T.H. Chan, School of Public Health.
“Calcium: What You Need to Know.” Family Doctor.
Peterlik, M. and WB Grant. “Calcium, vitamin D and cancer.” NCBI.2009.
“Calcium and Cancer Prevention.” National Cancer Institute.
“Calcium/ Vitamin D.” National Osteoporosis Foundation.
“Calcium.” National Institutes of Health.